tree a0cb94476cfb1bc09c2a806f71aaf36d1c0cb4cb
parent 79ff663754f4238bd1fe2e56f460c2f603c71b80
author Robert Griesemer <gri@golang.org> 1635368115 -0700
committer Robert Griesemer <gri@golang.org> 1635379884 +0000

cmd/compile/internal/types2: disallow lone type parameter on RHS of type declaration

We may revisit this decision in a future release. By disallowing this
for Go 1.18 we are ensuring that we don't lock in the generics design
in a place that may need to change later. (Type declarations are the
primary construct where it crucially matters what the underlying type
of a type parameter is.)

Comment out all tests that rely on this feature; add comments referring
to issue so we can find all places easily should we change our minds.

Fixes #45639.

Change-Id: I730510e4da66d3716d455a9071c7778a1e4a1152
Reviewed-on: https://go-review.googlesource.com/c/go/+/359177
Trust: Robert Griesemer <gri@golang.org>
Trust: Dan Scales <danscales@google.com>
Reviewed-by: Dan Scales <danscales@google.com>